<template>
  <div>
      <h5>我是子</h5>
      {{ arr }}
  </div>
</template>

<script>
export default {
    data() {
        return {
            arr: []
        }
    },
    mounted() {
        // this.$parent  拿到的是父组件的实例
        this.arr = this.$parent.arr
        console.log(this.$parent)
    }
}
</script>

<style>

</style>